1. Field of the Invention
The present invention relates to a control method/system for controlling downshifting in an at least partially automated mechanical transmission system. In particular, the present invention relates to the control of downshifting in a vehicular automated mechanical transmission system wherein the system senses conditions indicative of a downshift from a currently engaged gear ratio (GR) and evaluates, in sequence, the desirability of skip downshifts and then single downshifts and commands initiation of downshifts deemed desirable. More particularly, the present invention will sense conditions indicative of an operator's desire for performance and will modify the criteria for evaluating skip downshifts accordingly.
2. Description of the Prior Art
Fully or partially automated mechanical transmission systems for vehicular use are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 4,361,060; 4,648,290; 4,722,248; 4,850,236; 5,389,053; 5,487,004; 5,435,212 and 5,755,639.
Controls for automated mechanical transmission systems, especially wherein shifting is accomplished while maintaining the master clutch engaged, wherein single and/or skip shift feasibility is evaluated are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 4,576,065; 4,916,979; 5,335,566; 5,425,689; 5,272,939; 5,479,345; 5,533,946; 5,582,069; 5,620,392; 5,489,247; 5,490,063 and 5,509,867, the disclosures of which are incorporated herein by reference.